VirtualBox freezes on startup for 2 to 6 startups until it finally starts. I've got to kill it with xkill or killall and restart it before the GUI shows up correctly, else I only see a gray square. I will attach a strace and core dump file of the frozen state.

And the strace gets blocked at waitpid and won't move at all, even after 15 minutes.

I installed it with the Gentoo package manager but the Update check was indeed checked. I'll run it unchecked and see if I get the problem again, makes sense, once it ran, it was running fine for the rest of the day and update check was once a day :)

Ok, the reason for the freeze on Gentoo systems is that the Gentoo package installer removes the /opt/VirtualBox/VBoxSysInfo.sh script for some unknown reason. Is there any chance to ask the Gentoo maintainers to not do that or, if they insist on removing that script, at least providing a dummy script?